The upstream patch for this is far too big to backport, so for now, just drop the assert given it's somewhat harmless compared to not being able to build at all. https://jira.mongodb.org/browse/SERVER-65664 https://bugs.gentoo.org/855128 --- a/src/mongo/db/stats/counters.h +++ b/src/mongo/db/stats/counters.h @@ -221,8 +221,6 @@ private: AtomicWord requests{0}; }; CacheAligned _together{}; - static_assert(sizeof(decltype(_together)) <= stdx::hardware_constructive_interference_size, - "cache line spill"); CacheAligned> _logicalBytesOut{0};